A main structure of a panel for a thin film transistor-liquid crystal display (TFT-LCD) comprises an array substrate and a color filter substrate which are arranged to form a cell in an aligning manner, and a layer of crystal liquid sandwiched between the array substrate and the color filter substrate. Alignment films are arranged on inner surfaces of the array substrate and the color filter substrate. Alignment grooves are provided on surfaces of the alignment films to anchor liquid crystal molecules and provide a pretilt angle for the liquid crystal molecules. In existing technologies, the technology for aligning an alignment film comprises rubbing alignment technology and optical alignment technology. The optical alignment technology is a non-contact alignment process in which an alignment film is aligned by exposure to UV light. The optical alignment technology will not result in the generation of debris during the rubbing alignment process or adverse impact caused by static electricity, and the pretilt angle for liquid crystal is very small, thus image quality is very good. Therefore, the optical alignment technology is more and more widely used.
When the optical alignment technology is applied to vehicle-mounted liquid crystal display products or TV liquid crystal display products, due to high generation line and large-sized substrate of these products, the precision of control over edges in the coating process for the alignment film is very low. Therefore, when a sealant and the alignment films have a large overlap area after the array substrate and the color filter substrate are aligned to form a cell, the sealant is liable to peel off and conditions of the frame are poor. In order to overcome these technical problems, an optical alignment device may be revamped. However, the cost for the revamping is high, and debugging both during and after the revamping will affect the capacity.